With many neurological disorders, from Alzheimer's to ADHD, the first clue something is wrong may be atypical social behavior. Shirley Wang reports on Lunch Break. Photo: Getty Images.

This transcript has been automatically generated and may not be 100% accurate.

... I ... new claims to brain diseases such as Alzheimer's can be found actually in social behavior such as ... the ability to tell someone is lying or knowing how to express into the doctors now have ... new research to understand just why that is a joyous with the latest signs of hell calmness ... surely long in London ... sch chili will retire the changes in social behavior behavior ... books are a few examples I mention line but what are some others that would make doctors ... worry that brain disease might be applying ... way to think so the line when it's actually all forms of instant fear ... behaviors were insincere bad talk sale ... recognizing and sarcasm some notable is the ability to that ... um otherwise add to protect the social behaviors would be ... people who just after telling them they use to you on Vimeo let the left and pathetic when some ... kid telling people's feelings and an acting appropriately ... they may start to ignore ... so Sladek and or social norms on ... these kinds of changes oftentimes Apple I ate some kind of change in the brain that shows up first a social behaviors before you might notice it and other kinds of behavior such as ... planning or ... I'm ... thinking in Essen about and more organized way out of the social changes somehow come first is there a part of the blood brain Shirley that they think is specifically affected ... with imperative emotional responses ... yet there lots of different parts the brain that I think um work together ... and compare men anyone is probably helps to disrupt a lot of the functions that one in particular is a region called ... the info lot which is helpful ... in helping us recognize in import information so ... we might recognize that facial expression effective the import information should pay attention to that ... but for some people when they have this disruption ... that seems to stand for at least in part from this part of the brain ... the Macy's recognizing that that's really import information be shed ... on notice people's Index expressions of emotions and instead of people seem to stop ... stop noticing it and that might cause them to you that in appropriately ... or seem like they don't carry more about people's emotions so when we say someone when when we don't think someone is empathetic enough right if we don't think that they respond the correct way in a social situation or we just think they're ... cool are mean ... does that necessarily mean they have brain disease or is it a fine line between having PCs in just kind of being an awful person ... Wolf course on this never knew the answer that in general does not saying that anyone with a quarter or ... if sometimes on empathetic Cup hasn't rained in fees ... um but if it if you notice changes in the person that can can be a clue so for example ... there was a family member ... on who ... you know we use to be very I'm good at listening to other people and now this wouldn't seem to walk away we should talk ... that um could be a signal that there's something off ... um but I suppose like you said there might be people can just for personality reasons um it ended the year ... but some but that again and for that person perhaps not ... so much that it had rained is the isthe rather than something about the way the brain that that that that personality conducted on the point where they're talking about ways to repair these connections are appear these parts of the brain's where there seems to be this is this misfires of these these impairments ... I think it's fair said the Fed actually still appointed trend figure out what exactly goes awry ... on and they're trying really to figure out if they can figure ... out that a what goes wrong ... they can maybe use of the diagnostic information so not so much treatment yet I think that's really really really far down line that ... even in the sense that can help us ... paint a better clinical picture to help us diagnose add ... him ... to men shout or ... onto that earlier that would be banned notion right now that's very helpful thousands of priests and assigns it to someone has a family member friend would definitely be